It has long been known to provide ostomy appliances with relatively rigid convex pressure rings for the purpose of increasing stomal protrusion when such an appliance is worn, thereby aiding in the discharge of effluent directly into the pouch and also prolonging the effectiveness of the adhesive seal between the faceplate and peristomal skin surfaces. Reference may be had to U.S. Pat. Nos. 4,834,731, 5,618,276, 5,607,413, 5,730,735 and 5,501,678 for examples of appliances having such pressure rings. It has also been known to provide rigid convex adapters that may be attached to conventional ostomy faceplates as disclosed, for example, in U.S. Pat. Nos. 4,834,731, 5,004,464, 4,219,023, and 5,163,930.
A premise underlying the design of such convex faceplates and adapters is that a patient""s stoma is circular in outline, but studies have shown that is not necessarily the case. In one such study it was noted that stomas not only vary widely in size but that only 58% could be considered circular in shape with 42% being regarded as elliptical or irregular. Nordstrom, G. M. et al., Local Status of the Urinary Stomaxe2x80x94The Relation to Peristomal Skin Complications, Scand. J. Urol. Nephrol. 24:117-122 (1990). The possibility that a stoma may be non-circular in shape is also noted in European published application 0 888 760 A1, although that application relates to a planar faceplate rather than a convex one. Since convexity has been achieved in the past by providing a faceplate or adapter with a relatively stiff plastic element capable of causing stomal protrusion, such a ring has the capacity of causing considerable wearer discomfort should the opening of the ring fail to match the shape of a wearer""s stoma, or should direct contact between such a ring and the wearer""s stoma occur when the wearer bends sharply forward, changes positions, or simply moves about.
While it has been known to provide ostomy faceplates with soft, pliant barrier rings, or to supply soft gaskets that may be attached to such rings, such faceplates and gaskets do not function as convex pressure rings. See, for example, U.S. Pat. Nos. 4,213,458 and 4,710,182. Such faceplates/gaskets are commonly formed of a soft flowable material such as karaya, with such material serving as a sealant which flows or is displaced by finger pressure and use into contact with a stoma to prevent leakage and to avoid the excoriating effects that may result if stomal effluent contacts peristomal skin surfaces.
The present invention is concerned with a convex adapter that overcomes the shortcomings of prior convex faceplates and adapters and, specifically, one which may be easily and quickly adjusted in size and shape to match the size and shape of a wearer""s stoma. The adapter includes a ring formed entirely of a moisture-absorbing skin barrier material that is adhesive, soft, rubbery, non-distintegrating upon hydration, non-flowing, and shape-recoverable following compressive deformation. To achieve such objectives, the barrier material should have a continuous phase of an elastomeric adhesive blend including a styrene-olefin-styrene rubber, and a discontinuous phase of hydrocolloid particles dispersed throughout the rubbery adhesive phase.
An important aspect of this invention lies in providing the convex surface of the adapter ring of barrier material with a substantially inelastic and non-stretchable cover film that extends outwardly a substantial distance beyond the edges of the ring. The cover film must be removable from the ring and is preferably transparent, or least translucent, so that the rings"" outermost edges, and preferably the opening of a faceplate to which the adapter is to be adhered, may be seen through the film. In addition, the opposite surface of the barrier ring is covered by a removable release sheet which, like the cover film, is substantially non-stretchable. The release sheet is preferably of the same size and shape as the cover film, but both should be substantially larger than the faceplate to which the adapter ring is to be attached so as to facilitate removal of the cover film after the faceplate and convex adapter ring had been joined together.
It is well known to provide an adhesive faceplate of an ostomy appliance (either a one-piece appliance or a two-piece appliance) with a small circular starter opening which may then be cut to larger size (with scissors) to match the size and shape of a patient""s stoma. Alternatively, the faceplate may be manufactured with an opening sized and shaped (e.g., round or oval-shaped) to approximate the size and shape of a patient""s stoma. In either case, the method of use of the convex adapter of this invention may involve reshaping or reforming the adapter ring to match the size and shape of the opening of the faceplate. To that end, a user first strips away the non-stretchable release sheet and then, if the adapter ring sized and shaped to match a patient""s stoma, the user places the exposed planar surface of the adapter ring against the faceplate, with the openings of the two parts in register, and then strips away the non-stretchable cover film. Alternatively, and especially where the adapter ring must be stretched and reformed so that its opening substantially matches that of the faceplate opening, a user may first remove both the release sheet and the cover film from the adapter ring and then, gripping the adapter ring between the fingers of both hands, reshape the adapter ring and then adhere it to the faceplate.
Other advantages, features and objects of the invention will become apparent from the specification and drawings.